Four Seasons at Taku Glacier

My first visit to Taku Glacier was in late summer. The leaves of the willows growing on the spit of mud and heather being bulldozed by the advancing glacier were just starting to yellow in anticipation of winter, even though it was still August, fooled by the cold katabatic winds which consistently blow down from the upper reaches of the Juneau Icefield.

We had come to drill holes in the glacier using a pressurized jet of hot water. Doing this far from roads and electricity is something of an undertaking, requiring large water reservoirs, half a mile of hose, a diesel generator, several diesel boilers, and a giant pump, all of which would become perched on pedestals as the sun melted not shaded by our makeshift junkyard.

Fortunately, mechanical wizard Dale was there to keep everything working and organized, after a fashion

I managed the hoses, which were filled with hot water.

My own goal was to embed about a mile of instrumented ethernet cable within the glacier to measure its deformation, wobbling, and the pressure of the water at its base. This went reasonably well, so I helped others install seismometers,

and took some hikes to look at the sad remnants of Taku’s once robust calving front.

As a secondary objective, I wanted to install some instruments that would measure the flow in the river bubbling up from Taku’s snout.

How do you measure something like this? I tried burying pipes deep in the mud, with acoustic rangers pointing towards the water to measure its height. Unfortunately, these only ended up lasting a few weeks before the rains came and washed the instruments seaward, as I found out that autumn.

I don’t have any pictures of the following trip to Taku glacier in early October. As is wont to happen in Southeast Alaska, a persistent low had set itself up in the Pacific, and a steady stream of moisture continuously blasted the coast. In the days prior to the trip, we had been convinced that a weather window was opening. But as our flight day near the forecast steadily progressed from “scattered showers”, to “showers”, to “rain likely”, then to just “rain”, finally culminating in the foreboding “rain, heavy at times”. Heavy at times indeed. The combination of heavy rain and cleg kept us out two nights longer than expected, during which time we ate ramen noodles which had been presoaked, and oatmeal (my least favorite food). If I had a picture from that trip, it would be of either the inside of a Mountain Hardware Trango 3 and the obnoxious battery with an x through it that my Kindle displays when out of batteries, or just a miserable white fog.

Photo: Andy Aschwanden

Fortunately, our late winter trip was nicer. For one, the glacier was covered in six feet of snow, providing an opportunity to (finally) traipse about on skis (though the snow wasn’t quite thick enough to ameliorate the crevasse hazard).

Photo: Andy Aschwanden

It was a trip of extremes: bright sun gave way to soaking, freezing snain and back again. The dismay of having to probe for several hours to find my data loggers was offset by the delight of finding one working.

The horror of having to eat oatmeal was more than made up for by the novelty of eating Swiss Raclette, straight from the 600W specialized Raclette grill, in the space station in a snow storm.

Photo: Andy Aschwanden

The smoothed out crevasse fields lent a different scale to the place than during summer, when cracks offer punctuation marks to the landscape.

A trip to Taku in late spring offered an opportunity to see the local wildflowers in full bloom, and also to check up on all of the misbehavior my instruments had gotten up to during the melt season, when logger boxes were inundated with water, and mysterious physics left them overturned in large pools. Attrition was high.

This trip also offered an opportunity to pioneer new routes through the crevasse fields of the terminus, somewhere we’d always avoided in favor of safer passage. The goal was to repeat radar measurements of the bed taken both 10 and 20 years prior in order to assess how much erosion had occurred of the soft silts at the glacier sole.

OSHA approved?

The Norris River, which flows along the front into Taku Inlet was still low, at least compared to the first time I’d seen it 10 months earlier. At that time, it had been in the midst of a large outburst flood that littered the bar with icebergs and many of the trees that are still there today. Even when it’s low, it’s full of Xtratuff sucking quicksand.

We’re entirely dependent on the weather. It determines whether we can fly, and whether it’s even worth it to work. I can do more with a day of calm sunshine than with 5 days of wind and rain. I suppose that’s the difficulty of fiddling with exposed electronics in coastal Alaska. On this trip, the weather was excellent; the skies were often threatening, but rarely did they open up.

Though this kind of thing always makes you worried about your prospects of a helicopter exit.